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42 PT-7 sockets
#1

I'd like to replace the tube sockets on a pt7 but am having difficulty finding replacements. I haven't removed the old ones yet so I'm not sure my measurements are correct. The hole looks to be 1 1/16" and the center to center is
1 ⅜". Anyone know for sure? A source for these would be appreciated too.
Larry
#2

Pardon for asking a question but why would you want to do that?? Generally speaking unless the sockets are badly damaged it's not a great idea to do it on a whim. Sometimes you can have sockets that are burned from the heat/contact from the glass part of the tube but most of the time that happens with miniature tubes like the 50B/C5's and 35W4's not octal or loctals. Or arcing from contact to contact which burns the wafer. Just did one on my 660L, one of the 42 tube had been arcing and burn a carbon trace into the 6 pin socket. Or physical damage.
As you are finding (or not) loctal sockets are getting a bit harder to find these days. If I HAD to replace a loctal tube I would use the octal equivalent and use octal socket. Loctal are a bit of a pain.

GL
Terry
#3

 Try fleabay for loctal sockets, you may have to settle for some Chinese repro ones though if you want new, other then that you may have to use salvaged ones from a junk chassis. Just so you know the dimensions on the Chinese sockets are often given in millimeters and not in inches, so make sure you do the conversions first before ordering. 
  Again, as Terry asked, why do you want to replace the sockets anyhow? Are they broken? I replaced all of the sockets in a five tube AC set about a year ago that used really crappy wafer sockets, those were octals, and whilst I have the technique down I won't say that I would do it again without good reason. It might be easier just to find a chassis from a 42-PT4 or 42-PT2 or 42-PT10 with a broken cabinet and good sockets rather then replace the ones in the PT7 since they all used the same chassis.
Regards
Arran
#4

I'm having a difficult time removing the solder from the old sockets. I'm not the first or even second to rework this chassis and the sockets are loaded. The heat required is cooking the socket material.
#5

Sometimes it helps to put a little paste flux on the solder connection first, it will heat up the solder faster.
#6

(06-24-2016, 04:47 PM)Warren Wrote:  Sometimes it helps to put  a little paste flux on the solder connection first, it will heat up the solder faster.
Thanks I'll try that. They're pretty nasty.
#7

I had one tube socket that a ball of solder had flowed down into the portion of the socket where the tube pin needed to go. It took about 10 tries but I threaded some solder wick into the socket, heated the wick and socket and slowly pulled the wick up to try and suck out the solder. Eventually I got enough out to be able to get the tube pin to fit in.
#8

(06-24-2016, 12:11 PM)elfiself Wrote:  I'm having a difficult time removing the solder from the old sockets.  I'm not the first or even second to rework this chassis and the sockets are loaded.  The heat required is cooking the socket material.

 Try a solder sucker, one of those types with a spring loaded plunger works well, or one with the rubber bulb. With the rubber bulb ones the hole in the tip is often too small so it sometimes helps if you drill it out large enough to accept a finishing nail, after which the nail can be used to remove blockages. Sometimes it helps to ad a small dab of fresh solder to the tip of the iron or gun whilst trying to heat up and remove the old solder as well. Another thing that is useful for removing solder is a flat bladed jeweler's screwdriver, one of the medium sized ones like you would use to loosten the set screw on a knob, that you can use to push the molten lead off the terminal.
Regards
Arran
#9

solder wick ,,,with some flux (plumber's) rubbed on it,,,on both sides,,,in a heart beat it works,,Cheers
#10

Arran Wrote:
Sometimes it helps to ad a small dab of fresh solder to the tip of the iron or gun whilst trying to heat up and remove the old solder as well.


That's because you get some flux on your iron from the new solder (there is flux inside most solders) and it heats up he solder faster, easier. That's why I suggested using some extra flux. he could try that but if still hard some extra flux might be the trick.
#11

(06-25-2016, 10:48 PM)Warren Wrote:  Arran Wrote:
Sometimes it helps to ad a small dab of fresh solder to the tip of the iron or gun whilst trying to heat up and remove the old solder as well.


That's because you get some flux on your iron from the new solder (there is flux inside most solders) and it heats up he solder faster, easier. That's why I suggested using some extra flux. he could try that but if still hard some extra flux might be the trick.

 It isn't strictly the flux in the solder but also that the clean solder can make better thermal contact with the terminal to heat up the crusty old stuff.
Regards
Arran




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